Comparative study of pulse interactions in optical fiber transmission systems with different modulation formats

We compare nonlinear channel interactions in classical soliton, periodically-stationary dispersion-managed soliton (DMS), and chirped-return-to-zero (CRZ) systems. We studied multichannel systems with a single pulse in each channel and a more general case with multiple bit streams in each channel. First, we find that in classical soliton systems, the distortions are reversible, while in the DMS and CRZ systems they are not. Second, we find that the classical soliton system shows no increase in the degradation as the number of channels increases, while both the DMS and CRZ systems do show an increase in the degradation.